An entrepreneurial former cartoonist has turned his love of sharpening pencils into a profitable business that has seen him tour the United States to promote his recently published book on the craft.

David Rees, 39, started Artisan Pencil Sharpening almost two years ago after sharpening pencils for his job at the Census bureau reminded him how much he loved the practice, MSNBC reports.

"On our first day of training they had us all sharpen pencils because the (census) forms have to be filled out in pencils," he said.

"So we're all just sitting there sharpening pencils over a trash can, and I realized that sharpening pencils was really satisfying. It was something I hadn't done in years. I told myself that I had to figure out a way to get paid to sharpen pencils because it was so much fun."

For US$15 ($14.50) Mr Rees will sharpen a client's pencil with his $450 machine and send them back the shavings in a separate bag along with a certificate of authenticity.

The online business, run out of Mr Rees' home in Beacon, New York, provides customers with a General Pencil Company Semi-Hex #2 pencil, unless the client opts to send their own pencil in for sharpening.

While Mr Rees has clocked around 500 sales, he said most visitors to his website struggle to believe that the business is real, which has prompted him to launch an "Is This a Joke?" section of his site.

Mr Rees said most of his customers so far have made one-off purchases and the pencils have been commonly used as gifts for students about to sit their final exams at high school or college.

"Initially I thought I was going to become rich because I assumed it would function they way old-time knife sharpeners functioned — someone would pay me to sharpen the pencil, they would use it for a while, it would get dull, they would send it back to me, and I would re-sharpen it and refresh the point," Mr Rees said.

"I thought as that went on over the lifetime of the pencil I would make like 150 bucks per pencil. I think frankly that was a naive business model."

The success of Mr Rees’ business has even attracted the attention of publishers and he has just released a 224-page book titled How to Sharpen Pencils.

Mr Rees said he wants to use the book to encourage others to try their hand at pencil sharpening and he offers many of his own sharpening secrets.

But he isn't worried about competitors muscling in on his turf.

"It’s fine with me if other people start their own pencil-sharpening businesses," Mr Rees said.